A Hoxb13-driven reverse tetracycline transactivator system for conditional gene expression in the prostate.

Area of Science:

• * Molecular and developmental biology
• * Genetics and genomics
• * Cancer research

Background:

• * Genetically engineered mouse models are crucial for studying prostate development and diseases.
• * Constitutive models have limitations; inducible systems offer greater control.
• * A novel Tet-regulatory system using Hoxb13 transcriptional control elements was developed for prostate-specific gene expression.

Purpose of the Study:

• * To develop a tightly regulated, inducible transgenic system for prostate gene expression.
• * To enable precise temporal control of transgene expression in the prostate.
• * To facilitate detailed analyses of gene function in prostate pathobiology.

Main Methods:

• * Utilized recombineering technology to place the reverse tetracycline transactivator (rtTA) gene under Hoxb13 cis-regulatory control on a bacterial artificial chromosome.
• * Generated double transgenic mice by breeding Hoxb13-rtTA mice with a Tetracycline operator-Histone 2B-Green Fluorescent Protein (TetO-H2BGFP) reporter line.
• * Performed detailed reporter gene expression analyses, including doxycycline induction and withdrawal kinetics, in adult mice and embryos.

Main Results:

• * Doxycycline-dependent GFP expression was observed specifically in the prostate and distal colon epithelia.
• * Reporter gene mRNA was detected in the prostate within 6 hours of doxycycline exposure.
• * Gene expression was rapidly extinguished within 24 hours of doxycycline withdrawal and persisted after castration.

Conclusions:

• * The developed Hoxb13-rtTA transgenic system enables conditional Tet operator-driven transgene expression in the prostate.
• * This system provides a powerful tool for precise, temporally controlled gene function analyses in normal prostate and during disease.
• * These mice will advance the study of molecular events underlying prostate diseases by enabling detailed analyses in conjunction with other models.